git: rtld - Support static TLS bindings for late-loaded shared libraries

[Matthew Dillon]

commit eeb6957159b8d414a4ad6de31c473c8cd565972b
Author: Matthew Dillon <dillon at apollo.backplane.com>
Date:   Fri Aug 9 15:22:18 2019 -0700

    rtld - Support static TLS bindings for late-loaded shared libraries
    
    * Allow late (manual) dlopen()s to load shared libraries which
      use static TLS variables, as long as there is space.  Do proper
      late-binding and initialize the area for all threads.
    
    * rtld will cache a symbol lookup on first-need for:
      "_pthread_distribute_static_tls" and then call it as needed to
      initialize late-bound static TLS space.
    
      This symbol is weakly bounded to __libc_distribute_static_tls in libc,
      and strongly overridden by _libthread_distribute_static_tls in
      libthread_xu.
    
    * Fixes mesa glx-tls and others.
    
    * Test code from FreeBSD.  Also tested with other combinations
      including a pthread_create() and -static compilation.
    
    	https://github.com/dumbbell/test-tls-initial-exec

Summary of changes:
 include/dlfcn.h                          |  1 +
 lib/libc/gen/Symbol.map                  |  1 +
 lib/libc/gen/elf_utils.c                 | 18 +++++++
 lib/libc/include/libc_private.h          |  3 ++
 lib/libthread_xu/pthread.map             |  1 +
 lib/libthread_xu/thread/Makefile.inc     |  1 +
 lib/libthread_xu/thread/thr_distribute.c | 44 ++++++++++++++++
 libexec/rtld-elf/rtld.c                  | 86 +++++++++++++++++++++++++++-----
 libexec/rtld-elf/rtld.h                  |  2 +
 9 files changed, 144 insertions(+), 13 deletions(-)
 create mode 100644 lib/libthread_xu/thread/thr_distribute.c

http://gitweb.dragonflybsd.org/dragonfly.git/commitdiff/eeb6957159b8d414a4ad6de31c473c8cd565972b


-- 
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